Medical specialty dealing with diseases of the skin .
Its scientific basis was established in the mid-19th century by Ferdinand von Hebra (1816–1880), whose approach was based on microscopic examination of skin lesions. Starting in the 1930s, an emphasis on biochemistry and physiology led to more sophisticated and effective treatments. Dermatology deals with fungal diseases, skin cancers, psoriasis , and life-threatening skin diseases such as pemphigus, scleroderma , and lupus erythematosus .